lame -h -V 3 mymusic.wav
This uses variable bitrate mode with -h (high quality but slightly slower) and produces the following frame bitrate histogram:
LAME 3.100 64bits (http://lame.sf.net)
Using polyphase lowpass filter, transition band: 18000 Hz - 18581 Hz
Encoding mymusic.wav
to mymusic.mp3
Encoding as 48 kHz j-stereo MPEG-1 Layer III VBR(q=3)
Frame | CPU time/estim | REAL time/estim | play/CPU | ETA
11459/11459 (100%)| 0:05/ 0:05| 0:05/ 0:05| 49.421x| 0:00
32 [ 118] %*****
40 [ 0]
48 [ 0]
56 [ 0]
64 [ 1] *
80 [ 0]
96 [ 26] **
112 [ 280] %************
128 [ 1412] %%%%%%%%%*******************************************************
160 [ 4372] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%***************************************************************************************************************************************************
192 [ 2319] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*************************************************************
224 [ 864] %%%%%%%%%%%%***************************
256 [ 1206] %%%%%%%%%%%%%%%%%**************************************
320 [ 861] %%%%%%%%%%%%%%%%***********************
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
kbps LR MS % long switch short %
186.8 28.3 71.7 70.8 12.5 16.7
Writing LAME Tag...done
ReplayGain: -9.7dB